Mata is expected to undergo a medical on Thursday, with a source close to the club-record deal telling Press Association Sport on Wednesday that the transfer is "close" to being concluded.

However, Moyes opted not to speak about it following United's painful penalty shoot-out loss at Old Trafford.

Members of the media were informed before the post-match press conference that Moyes would be answering questions on the game only and when asked afterwards about Mata, the Scot said simply: "We are not saying anything."

Nevertheless, it would now be a major surprise if Mata - who is likely to cost around the £40million mark - was not part of Moyes' squad for United's next match, against Ole Gunnar Solskjaer's Cardiff at Old Trafford on January 28.

And on the evidence of yet another toothless performance from United, Mata's arrival cannot come quickly enough.

Mata is thought to have missed training on Wednesday and is said to have indicated to friends he was destined for Old Trafford.

A move for the Spain international would make sense from virtually every angle.

Although Gary Neville pointed out earlier this week his arrival would represent a change of tactic for United, who have traditionally relied upon two wingers, the knowledge that none of Antonio Valencia, Ashley Young and Nani have sparkled under Moyes this season means ditching the concept would not be a hardship.

In addition, it would prove to United fans their club was serious about addressing the sharp decline in fortunes experienced since Sir Alex Ferguson's departure, even if it cannot guarantee the Champions League spot they crave.

Speaking on Sky Sports 1 on Wednesday evening, Neville said: "This is a number 10 who plays in a wide area, and I'm imagining that Robin van Persie and Wayne Rooney would take up the predominant roles, but he's a huge talent.

"He can spot a pass. They've lacked creativity at times Manchester United in the final third and he definitely has that.

"I think that this is a big transfer window for them. If they can pull in a big signing it would lift (executive vice-chairman) Ed Woodward, it would lift the fans and it will give everybody at the club a boost. They need that here."

For Mata, it would end a tortuous few months, where he has left Jose Mourinho unimpressed and become increasingly marginalised, thereby enhancing his chances of making Spain's World Cup squad.

Chelsea would bank a far larger fee than they could hope to attract from Mata's other suitors - Barcelona and Paris St Germain - and whilst it would be unusual for them to sell to a fellow Premier League giant, Mourinho knows United are not a threat in this season's competition.

Indeed, given United have played Chelsea twice but must still encounter Arsenal and Manchester City in the run-in, it could be argued Mourinho is strengthening his own team's position.

For Moyes, it can only be the start of what is sure to be an extensive rebuilding programme, that is not likely to be completed for another 18 months, with the Scot adamant he is not prepared to rush his work.